<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			#d1{
				width: 12.5rem;
				height: 6.25rem;
				background-color: green;
				position: relative;
				top: 6.25rem;
				left: 6.25rem;
				opacity: 0.8;
			}
			#d2{
				width: 12.5rem;
				height: 6.25rem;
				background-color: yellow;
				position: relative;
				left: 12.5rem;
				opacity: 0.8;
			}
			#d3{
				width:  6.25rem;
				height:12.5rem;
				background-color: red;
				position: relative;
				top: -12.5rem;
				left: 12.5rem;
				opacity: 0.7;
			}
			#d4{
				width:  6.25rem;
				height:12.5rem;
				background-color: blue;
				position: relative;
				top: -18.75rem;
				left: 12.5rem;
				opacity: 0.6;
			}
		</style>
	</head>
	<body>
		<div id="d1"></div>
		<div id="d2"></div>
		<div id="d3"></div>
		<div id="d4"></div>
	</body>
</html>
